Plan B
by Jace5000
Summary: In the sequel to Plan A, Jace, Clary, and the gang have to battle Sebastian and Jax's malicious mango plan.
1. Chapter 1

**I do not own the Mortal Instruments (Cassandra Clare)**

Chapter 1:

Year 2016:

Sebastian stretched as he got out of bed. Over the years he had gotten used to living in a different body. Although, it was still strange to sometimes hear another person thinking inside his head. At least his speed and strength had transferred to his new body along with his ghost.

After getting breakfast, Sebastian went to check on the mango tree. Perhaps it was time to send the Institute more mangoes. Normally he only sent them once a year, but now the children were old enough that if his demoness was going to affect them it would have. Yes. It was time to reveal himself to his sister. It was time to take her.

Sebastian smiled as he picked the mangoes. He wouldn't send as many. It wasn't the normal time he sent mangoes, and when Clarissa figured out who was sending them, he doubted the mangoes would actually be eaten.

"Carl, I have a delivery to make," Sebastian said.

#

Today was Stephen's sixth birthday. Clary and Jace were currently running around trying to set up his surprise party. They had left Stephen with Alec and Magnus so that he wouldn't see what they were doing.

Clary was busy wrapping Stephen's gifts when there was a knock on the Institute door. Clary quickly made her way to the door and opened it. On the other side was a large cardboard shipping box. It was the same kind of box that the mangoes had been coming in for the past four years. The only difference was this time the box was addressed to Stephen. Clary brought the box inside to the kitchen.

"What's that?" Jace asked walking into the kitchen.

"It's a present for Stephen," Clary answered. "I think it's mangoes. It's in the same kind of box."

"I thought the mangoes only came once a year," Jace commented.

"They do," Clary affirmed. "It looks like our mango supplier decided to give Stephen mangoes for his birthday."

"Should we open it?" Jace inquired. "You know to make sure it isn't dangerous."

"That might be a good idea," Clary agreed.

Inside the box were a bunch of mangoes. Sitting on top of the mangoes, were two envelopes. One addressed to Stephen and the other addressed to Clary and Jace.

Clary opened the envelope addressed to her and Jace and began reading it.

 _Dear Sister and Brother,_

 _I thought it would be nice to send an extra box of mangoes for my nephew's sixth birthday. Don't worry. You will still get the regular shipment of mangoes. Enjoy!_

 _Your dear brother,_

 _Sebastian_

Clary dropped the letter stunned after she read it. "It can't be... He can't be back. How would he get back?" she was in denial.

"Clary, I'm pretty sure he's back. Either that or someone is impersonating him. Either way, this is bad. We need to tell the others," Jace said.

"What are we going to do?" Clary buried her face in her hands.

Jace put a comforting arm around her shoulders. "We'll get through this. If he's back, then we'll kick his ass like we have always done. Come on, right now we have a birthday party to set up."

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	2. Chapter 2

Chapter 2:

"Happy birthday!" everyone shouted as Clary led Stephen into the room.

Stephen startled, stepping back a step before grinning when he realized what was going on. Clary watched as he ran over to Elizabeth or Liz as she preferred to be called.

Clary stood next to Jace. "Have you told the others about the mangoes yet?" Clary asked, quietly.

"No, I figured we should do it after the party, so we don't ruin anyone's good time," Jace replied.

"OK, but we can't put it off too long," Clary said.

"Mommy, Daddy, come on let's go open presents and eat ice cream cake!" Stephen shouted, running up to Jace and Clary.

Jace laughed and picked up his son, tickling him. "I'm the tickle monster, and I'm going to tickle you!" he growled playfully at Stephen.

"Mommy, help! The tickle monster's got me!" Stephen shouted, laughing as Jace tickled him.

Clary laughed following along behind Jace and Stephen as they ran over to the cake. When she got there Jace handed her a piece.

"I think that went well," Isabelle commented as she helped clean up the room the party had been in.

The party had ended about an hour ago and the children had been put to bed. It had been easy getting them to go to sleep since they were exhausted from playing at the party.

"We have something to tell you guys," Clary told them.

"What?" Alec asked.

"Come on, we'll show you," Jace began walking towards the kitchen.

In the kitchen he pulled out the box of mangoes they had hidden in the pantry.

"Mangoes? So what? You've been getting boxes of Mangoes for several years now. I don't see the big deal," Magnus said.

"Read this," Clary handed them the note from Sebastian.

"What does this mean?" Simon asked.

"It means that Sebastian is back. Again," Clary replied.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	3. Chapter 3

Chapter 3:

"How can he be back?" Isabelle asked.

"I don't know. The only way I think he could have come back is if Jax brought him back," Jace answered.

"But he's in the mundie foster care system," Alec protested.

"We should still check up on him to make sure," Clary said.

"Should we tell the Clave?" Simon asked.

"Not yet. For all we know this is someone's idea of a sick joke," Jace replied.

"What kind of person would do something like this though?" Isabelle inquired.

"I have no idea, but if it was some person playing a prank they will soon learn just how severe the consequences can be," Jace promised.

"How are we supposed to find this person in the first place?" Alec asked.

"We know they must live in a warm climate if they are really growing mangoes," Jace reasoned.

"That still leaves us with lots of space to search," Simon observed.

"We should check on Jax before we get carried away," Magnus piped up.

#

"They're searching for us," Carl told Sebastian.

"I know," Sebastian replied.

"What should we do? Do you want me to block them from tracking us?" Carl asked.

"No. I want my sister. What better way to get her than to have her come right to me?" Sebastian replied a smirk playing around his lips.

"I hope you know what you're doing," Carl muttered low enough that he probably though Sebastian wouldn't hear him.

"I do," Sebastian replied, smirking a cruel smirk. Carl flushed and muttered an apology while scurrying away.

Carl didn't know how he had gotten mixed up in this mess. One minute he was helping two small boys get back to their family and the next he was caught up in one of the most infamous shadowhunter wars. He just hoped he survived.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	4. Chapter 4

Chapter 4:

"I've found Jax," Magnus announced.

"Where?" Jace asked.

They were all in Magnus and Alec's apartment, sitting around waiting for Magnus to locate Jax. Magnus had said it wouldn't take long. Magnus's and the rest of the group's definition of long must have been different, since it took three hours.

"He's in Florida. He was adopted by a man named Carl," Magnus supplied.

"How come the name Carl sounds so familiar?" Simon pondered.

"Wasn't Carl the warlock Jax and Jude used to find us?" Clary inquired.

"I believe it was. We should verify with Jude," Magnus said.

"Isn't he at the academy?" Alec asked.

"Not at the moment. He's at the Los Angeles Institute currently. We could give him a call," Clary suggested.

They called Jude.

"Hello?" Jude answered.

"Hey, Jude, we need to ask you a question," Jace greeted.

"What is it?" Jude asked.

"The warlock you and Jax used to find us, was his name Carl?" Jace questioned.

"Yes, why?" Jude asked.

"He may be helping Jax bring Sebastian back," Jace said.

The phone was on speaker phone and the others were all listening quietly.

"This is bad. Do you want me to come there and help you guys?" Jude asked.

"I don't think that will be necessary," Jace replied.

"OK, but still keep me informed," Jude requested.

"We will. Bye," Jace said, hanging up.

"So what do we do now, if Carl really has helped bring Sebastian back?" Isabelle asked.

"I think it's time to pay Jax and Carl a visit," Jace said.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	5. Chapter 5

Chapter 5:

They're coming, Sebastian thought with a sinister glee. Soon he'd have his sister. Soon Angel Boy and their sidekicks would be out of the way. All he had to do was wait for them to come and fall into the trap he had set.

#

"Is this the place?" Jace asked, looking to Magnus.

"I believe so," Magnus answered.

They stood in front of a large beech house in the Florida Keys. It was a nice house with stone walls and windows that couldn't be seen through from the outside.

"What do we do now?" Alec inquired.

"Knock?" Clary suggested.

Jace knocked on the door. A minute later it was opened by a man.

"Hello?" the man asked.

"Hi, are you the warlock Carl?" Isabelle asked.

"Izzy," Simon hissed quietly.

"I am," Carl said.

"Did you adopt a boy by the name of Jax?" Jace questioned.

"I did. Why?" Carl inquired.

"We would like to speak with him," Magnus said.

"Sure, he's inside," Carl took a step back allowing them entry.

Inside the house was lavishly decorated with expensive vases and crystal chandeliers.

"Se… Jax, there are some people here to see you!" Carl shouted.

A few minutes later a boy of about nineteen entered the room.

"Well, well, well, if it isn't the people who abandoned me to the life of a mundane," Jax drawled.

"If I recall correctly, you tried to bring Sebastian back, and becoming a mundie was your punishment," Isabelle snapped.

"So what brings you here?" Jax asked, ignoring Isabelle's outburst.

"We want to know if you have been trying to bring Sebastian back again," Jace said.

"I haven't," Jax answered.

"Would you mind if we had a look around?" Clary inquired.

"Not at all," Jax grinned.

"Alec, you and Magnus search that way. Izzy and Simon, you guys can go that way. Clary and I will check this way," Jace said, pointing in different directions.

"You're splitting us up," Simon asked, slightly disbelievingly.

"We'll cover more ground that way," Jace told them.

The others nodded in agreement. Jace and Clary began to head in the direction Jace had indicated they would go. Jax fell into step beside them.

"I can assure you, you won't find anything," Jax said.

"We'd rather check for ourselves," Jace countered.

Jax fell back after that, and Jace and Clary continued forward, looking for any sign of Sebastian.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	6. Chapter 6

Chapter 6:

Clary glanced over her shoulder just in time to see Jax raising a large kitchen knife, aiming for Jace's back.

"What out!" Clary screamed, shoving Jace to the side.

Jace spun, pulling a seraph blade from his weapons belt.

"Why are you trying to kill us?" Jace demanded.

"Oh, I'm not trying to kill you both; I'm only trying to kill you, Angel Boy," Jax said.

"Okay, why are you trying to kill me?" Jace rephrased.

"Isn't obvious? So I can have my sister of course!"

"Sister? I don't recall you having a sister," Jace said.

"You really are as stupid as you look, aren't you, Angel Boy," Jax chuckled, retreating down the hall and out of sight.

"What's going on?" Isabelle asked, slightly out of breath as she and Simon raced towards the place Jace and Clary were standing.

"We heard a scream. Who's hurt?" Alec questioned rushing in from another direction with Magnus.

"Nobody's hurt," Jace reassured them.

"Then what happened?" Simon inquired.

"Jax attacked Jace," Clary told them.

"Why would he do that? I thought he had nothing to hide," Isabelle said.

"He said he wanted his sister," Jace answered.

"His sister? I didn't think he had a sister," Alec commented.

"Did he also call you angel boy?" Magnus inquired of Jace.

"Yes, come to think of, he did. Why?"

"I was afraid of this," Magnus murmured.

"Afraid of what?" Alec asked.

"I believe Jax has brought Sebastian back, and allowed him to possess his body," Magnus said.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	7. Chapter 7

Chapter 7:

Clary felt as if a ton of bricks had been dropped on her. Sebastian was in Jax's body? How could this be? Why would someone want to bring Sebastian back? What would it take to get rid of her brother permanently?

"Clary, are you alright?" Jace asked, concern lacing his voice.

"I'm fine. It's just that it seems like every time we try to get rid of Sebastian, he always finds a way to come back and torment us," Clary replied.

"It will be okay, Clary. We will get rid of him just like we did every other time. By now we should be able to call ourselves Sebastian Slayers," Jace put a comforting arm around her. "Our slogan could be, 'Sebastian Slayers hard at work, ridding the world of that evil smirk!' What do think?"

"I think you should stick to demon hunting," Simon said, dryly.

"Hey!" Jace protested, glaring at Simon.

"I have to agree with Simon on this one," Clary giggled.

"You people just don't appreciate the beauty of it," Jace grumbled.

"That's because there is no beauty to appreciate," Isabelle teased.

"Teasing each other won't help us come up with a plan to destroy Sebastian," Alec observed.

"Alec is right," Magnus agreed.

"How are we supposed to get rid of him?" Simon asked.

#

Sebastian listened from the shadows as his little sister and her friends planned his demise.

"I don't know," he heard Jace say.

"I say we should get out of here first," Simon voted.

"That's the best idea I've heard so far," Magnus agreed.

No! They couldn't leave! If they did, he wouldn't hear their plan. Also that meant he would have to hunt them down. Hunting could be a problem, since his tree wasn't easily portable, and mango trees, by nature, were limited to warm climates.

"Carl, I need you to make it so nobody can leave or enter the house," Sebastian texted.

"Done," came the reply a minute later.

Sebastian smirked. "You can try to leave, but you won't be able to," he whispered quietly to himself.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	8. Chapter 8

**Quick Q &A:**

 **Question: _How old is Jax?_**

 **Answer: _He should be a teenager about 18 or 19 years old._**

 **Thank you to those interested enough to ask!**

Chapter 8:

The gang slowly and cautiously found their way to the front door, watching for any expected surprises Sebastian may have planned for them. Jace reached out and grasped the door handle. He twisted it and pulled. The door stayed shut. Jace pulled again and again. The door wouldn't budge.

"The door won't open," Jace said, finally giving up.

"Is it locked?" Simon asked.

"Yes, that's why it won't open, because I don't know how to unlock a door," Jace retorted, sarcastically.

"Just trying to eliminate all possibilities. Jeesh," Simon muttered.

"Here let me try an open rune," Clary suggested.

Clary pulled out her stele and moved in front of the door. She began to draw the open rune. The black lines of the rune swirled out from the tip of the stele, but vanished into the wood as quickly as she drew them. "I can't draw an open rune on this door!" Clary exclaimed in surprise.

"There must be a spell on it," Isabelle observed.

"How about we try another door," Alec proposed.

They made their way to another door at the back of the house. Again Jace attempted to open it, and again it wouldn't open. Again Clary tried to draw an open rune on the door, and again the rune was swallowed up by the wood as quickly as Clary could draw.

"Something must be keeping all the doors from being opened," Magnus realized.

"What about windows? Can we get out through one of them?" Clary asked.

"Maybe. It's possible that the spell keeping the doors closed isn't on the windows. But I'm guessing that Sebastian doesn't want us getting out, and the windows will be unopenable as well," Magnus said.

Jace walked over to the nearest window and tried to push it open. It wouldn't move. He checked the lock. It was unlocked. He tried to open it again. When the window wouldn't open, he tried a couple others. None of them would open. He tried to smash one of the windows with the hilt of his seraph blade, but the glass didn't so much as crack. Clary tried to draw an open rune on one of the windows, and the lines of the rune bled through the glass and disappeared as quickly as she drew.

"It looks like we're trapped inside the house," Jace concluded.

"With Sebastian," Simon added.

"Can we call anybody?" Clary inquired.

They each pulled out their phones, but before they could place any calls a voice spoke from behind them.

"That won't work either."

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	9. Chapter 9

Chapter 9:

Clary whirled to face the tall, broad shouldered, white haired, black eyed boy behind them.

"What do you mean it won't work? Why wouldn't our phones work?" Clary demanded.

"The spell that keeps you from leaving also keeps you from contacting anyone outside the house," Sebastian enlightened.

"How do we know you aren't lying?" Jace challenged.

"I'm not lying," Sebastian stated, simply.

"What do you want? Why are you keeping us locked up here?" Isabelle asked.

"I only want what is mine," Sebastian answered.

His calm demeanor was starting to irritate Clary. Why was he so calm? Usually, he was extremely erratic.

"You'll never get Clary," Jace snarled. "Now let us go!"

"No," Sebastian replied.

Sebastian rushed at them. It seemed that even though he was no longer in his own body, he had retained his demonic speed.

Sebastian slashed his sword at Jace. At the last second Jace blocked Sebastian's blow with his own seraph blade. Isabelle flicked her whip at Sebastian, lashing out, catching him around the ankle. She yanked her whip back, sending Sebastian sprawling to the ground.

Jace ducked just as a flying ball of neon orange sparks flew over his head. They turned to see Carl standing there with his hand out stretched a few stray sparks falling to the floor.

"If we take out the warlock the spell will be broken," Magnus informed.

Alec aimed and shot an arrow at Carl. The arrow swiftly sailed through the air, finding it's mark in Carl's forearm. Carl shouted in pain.

"I felt the spell fall. Let's go," Magnus said.

The group ran. The came to the front door and yanked it open. Simon and Isabelle were the first to exit, followed by Alec and Magnus. Jace grabbed Clary's hand and pulled her with him as he ran outside. Just as Jace crossed the thresh hold to the house a pulsing wave of magic knocked them apart. When Jace regained his balance he looked around for Clary. He saw her still inside the house. He rushed forward to grab her, but was knocked back by an invisible barrier.

"Clary!" Jace called.

Clary ran forward and tried to exit the house, but was blocked by the same barrier that had kept Jace from entering.

"Magnus what is going on? Why can't Clary leave the house?" Jace interrogated.

"It seems Sebastian has set up a trap to separate us from Clary," Magnus answered.

Right then Jace heard a scream come from Clary's direction. He looked over to see the doors to the house swinging closed. Right before they completely closed, Jace saw Sebastian come up behind Clary and drag her back.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	10. Chapter 10

Chapter 10:

Clary screamed, struggling against Sebastian's grip. "Let me go!" she screeched.

"Never, My Darling Little Sister."

Clary could hear the smugness in his tone. "Why? Why are you doing this? Why do you keep coming after me? What will it take to get rid of you forever?" question after question kept pouring from Clary's mouth.

"I do this because you are my sister. We share the same blood. We are family, and I won't let you go," Sebastian hissed in her ear. "And as for getting rid of me, I can assure you, you will never be rid of me. No matter what you do."

Clary could feel him smirking. Sebastian dragged Clary into a room. He pushed her to the ground, turning he left without another word.

#

"How are we supposed to get into the mansion?" Jace asked, pacing back and forth in Magnus's living room.

They had gone back to Magnus and Alec's apartment after being locked out of Sebastian's mansion.

"We need something that he will either let in or draw him out. Some kind of bait," Isabelle said.

"We also need to figure out a way to remove him from Jax's body," Magnus reminded them.

"How are we going to do that? We don't know what he's tied to, and this time we don't have somebody on his side who will betray him," Jace snapped.

"Simon?" Isabelle asked, seeing the look of concentration on his face.

"I just feel like I'm forgetting about something," Simon muttered. "Liz is with Luke and Jocelyn right?"

"Of course, they offered to watch Liz and Stephen while we figured this stuff out," Isabelle replied.

"How about the stove? Did you turn that off?" Simon questioned.

"Yes the stove is off," Jace snapped. "This is no time for silly mundie questions."

"I just think I'm forgetting something," Simon said, scratching his head in frustration.

"Jude!" Magnus shouted.

"What?" Simon inquired looking at Magnus along with the others. "I don't think Jude is what I'm forgetting, Magnus."

"No. Jude. He betrayed Jax and Sebastian last time, so if we use him for bait Sebastian might just take it, wanting revenge," Magnus reminded.

"That could work," Jace agreed. "But it still doesn't give us a way to destroy Sebastian."

"We'll continue searching for a way to destroy him. For now, we should call Jude and inform him of our plan to use him as bait," Alec said.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	11. Chapter 11

Chapter: 11

"You want to use me as bait?" Jude asked, incredulously.

He had arrived at Magnus's apartment just a few minutes ago.

"Yes. We think that if Sebastian and Jax hold a grudge against you for foiling their first attempt to bring Sebastian back, they may decide to let you into the mansion. We can slip in right behind you, take out Sebastian for good, and rescue Clary," Magnus explained.

"Sounds like a good plan, but what happens if you aren't able to slip in before Sebastian blocks you?" Jude questioned.

"Then you'll have to take him out," Jace said.

"Or get the warlock to lower the barrier keeping us out," Simon added.

"And if I can't?"

"Then… we'll make sure your ashes are put in the City of Bones," Jace smiled.

Jude frowned. "I don't get it. How did you know Sebastian was back in the first place?"

"We received a box of mangoes from him, saying that he was back," Isabelle answered.

"MANGOES!" Simon shouted.

"What about mangoes?" Magnus asked.

"That's what I was forgetting. There's something about the mangoes," Simon enlightened them.

"I'm still not getting it. What about the mangoes?" Alec questioned.

"Think about it. Why would Sebastian just send us boxes and boxes of mangoes for the past three years?" Simon asked.

"What would he have done? It's not like he poisoned them. We would have figured that out a long time ago," Isabelle said.

"I don't know exactly, but I do know something is up with those mangoes," Simon said.

"The tie!" Magnus exclaimed.

"What?" Jace asked.

"The tie. To bring Sebastian back Jax had to tie his ghost to an object, but that wouldn't have caused Sebastian to possess Jax's body. Jax would have had to eat whatever he tied Sebastian to. What if he tied him to a Mango and ate the edible part of the mango? Sebastian would have been able to possess Jax's body, but the pit would have still held part of him. What if he grew the pit into a tree and began sending corrupt mangoes to the Institute?" Magnus elucidated.

"Are you saying we've been feeding our children Sebastian ghosty bits for the past three years?" Jace asked, angrily.

"Perhaps," Magnus replied. "If that's the case, we'll need to destroy not only Sebastian in Jax's body, but also the mango tree."

"Alright that's it! Jude, you'll be bait. When we get inside, I'll kill Sebastian. Magnus and Alec, you find and destroy the mango tree. Isabelle, Simon, and Jude, you find Clary and get her to safety," Jace declared.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	12. Chapter 12

Chapter 12:

After Sebastian left, Clary got up and began searching the room for anything she could use to escape. Her search was quickly over. The room didn't have much of anything in it. On one side of the room was an empty closet. Literally, the closet didn't even have shelves or a rod to hang clothes on. In the room was a small mattress laying on the ground. About five feet away there was a hole in the wall. The hole looked like it was just big enough for a large rat… or maybe a ferret. Clary hoped that if anything lived in there it wouldn't be a nuisance to her. Other than that there was nothing she could use as a weapon. Maybe she could push the mattress onto him? She highly doubted that would do much.

Clary had retreated to the mattress, positioning herself so that she could keep an eye on the door. It seemed like several hours passed. Finally, she heard the door knob turn. Clary sat up straighter, watching to see who would enter.

Sebastian entered the room, carrying a covered tray. He strode over to the mattress. He sat down opposite Clary and set the tray between them.

"Eat," Sebastian commanded, removing the covering.

On the tray was a cold sandwich, some chips, and a bottle of water.

"No," Clary refused, tilting her head away stubbornly.

"Eat. Or I will hold you down and force the food down your throat," Sebastian threatened.

Clary hesitantly reached out, taking the sandwich from the plate. She nibbled slowly, trying to make the food last as long as possible. It wasn't that she wasn't hungry; she was. She also dreaded whatever Sebastian had planned next.

When the plate was finally empty, Sebastian set it on the floor beside the mattress. "Now," Sebastian grinned a positively evil grin, "we get down to business."

#

"I don't get it. Why does Jax feel so loyal to Sebastian?" Simon asked. "I honestly can't think of any reason he would."

They were currently getting ready to leave for Sebastian's mansion. Jace, Alec, and Isabelle, had all left to get more weapons from the Institute, Simon already had weapons and was in Magnus's kitchen, Magnus dressed in his glittery armor was currently standing in front of the mirror making sure his hair looked right, and Jude was in the kitchen with Simon, waiting for the others.

"Valentine had decided to raise us much in the same manner as he did Jace and Sebastian. He kept us in another part of Brocelind Forest, training us. Unfortunately, we weren't as strong as Jace or Sebastian, so Valentine decided we were useless to him. He told us we were too weak for what he had planned. Valentine was going to kill us. Fortunately for us, Sebastian had decided to follow him and decided he didn't want us dead. He took us away before Valentine had a chance to kill us. He took care of us until the day he died," Jude elucidated.

"Wow," Simon muttered. "If he was so good to you, why did you betray him?"

"He was good to us most of the time, but I began to notice small things about him. He would blow up at the smallest mistake. I once saw him kill one of the endarkened for merely dropping his sword. Sebastian wasn't stable. Also, when I got to know you, I couldn't stand the idea of Sebastian harming any of you," Jude answered.

"Is everybody ready to go?" Jace asked, barging into the apartment before Simon could ask any more questions.

"I believe we are," Magnus replied. "Let me make a portal and we can be on our way."

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	13. Chapter 13

Chapter 13:

Sebastian stalked Clary across the room. She continued to back up until her back hit the wall. She couldn't go any further. She was trapped. Sebastian kept coming towards her, not stopping until he was almost pressed against her. He brought his hand up and stroked her hair away from her face.

"Okay, I just have to say, I feel a little weird about this," Clary stated. "And it's not just because you're my brother. Here I am twenty-five, and my nineteen year old older brother is hitting on me. I honestly don't think anybody else has ever been able to say that."

"Does it even matter that I am your brother? I don't have the same body as before, so it's not like we share the same blood. Technically we aren't related anymore," Sebastian pointed out.

"Yes it matters. I don't care we don't share the same blood anymore. You're still my brother. You're still a monster. Why can't you just leave me alone," Clary hissed, shoving him.

An angry tick started in Sebastian's jaw. He didn't move a millimeter when Clary shoved him.

"It doesn't matter," Sebastian insisted, leaning closer to her.

Clary looked around desperately, searching for anything she could use. She knew it was hopeless. She shut her eyes and braced herself. Before anything could happen there was a knock on the door. Sebastian paused and glared at the door as if he could incinerate the person on the other side who dared interrupted him. The knock came again, getting more insistent.

Sebastian stalked over to the door and ripped it open to reveal Carl raising his hand to knock again.

"What?" Sebastian growled, angrily.

"Jude is outside. I just thought you would like to know," Carl whimpered.

"The Jude that betrayed me?" Sebastian raised his eyebrow in question.

"The same one," Carl answered.

"Let him in. Make sure he is well taken care of until I can attend to him," Sebastian ordered.

Sebastian and Carl continued talking. Clary was distracted from them by a soft skittering sound. She looked down to see a ferret had just left the hole. An idea began to form. Yes, that would do just perfectly Clary thought, inwardly smirking.

#

Jace watched as Carl opened the door and ushered Jude inside. Jace and the others rushed forward and entered the house right behind Jude.

"What the… What's going on?" Carl demanded.

"We're rescuing our friend," Magnus answered. "I'm afraid you won't be awake for it." Magnus snapped his fingers and blue sparks rained down on Carl. Carl collapsed to the ground, unconscious.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	14. Chapter 14

Chapter 14:

Clary bent down and picked up the ferret before Sebastian could notice. She held the ferret down by her side, hoping Sebastian wouldn't notice. The ferret struggled, scratching up her hand. At least it stayed quiet. She hoped she wouldn't get some kind of disease.

Sebastian turned around and strode over to Clary, not noticing the struggling ferret in her hand.

"Now where were we?" he asked.

Sebastian brought his hand up to cup the base of her head. He pulled her face closer to his, and she let him. She needed him to be too distracted to notice what she was doing. She brought her unoccupied hand up as if she were going to rest it on his hip. Instead, she curled her fingers around the waist band of his loose fitting sweat pants, drawing the elastic away from his stomach. She felt his lips curl into a smile against her cheek almost on her lips. As fast as she could, she brought the struggling ferret up and dropped it into his pants.

Suffice it to say, neither the ferret nor Sebastian was happy about this. Sebastian leaped away from Clary. He began to do something that looked like a cross between the pee pee dance and something you would see in a Micheal Jackson video. He was making all sorts of sounds. Lots of them sounded like a cross between a scream and yelp.

Clary didn't wait around for him to recover. She ran to the door. She yanked it open and raced out of the room, sending a silent apology to the ferret for subjecting it to Sebastian's wrath. She raced down hallway after hallway, trying to find her way out.

"Clary?! Clary where are you?!" Clary heard someone who sounded a lot like Jace shout.

Clary changed direction heading for Jace. "Jace?!" she called out, hoping it was actually Jace and not a trick of Sebastian's.

#

Jace began searching the house, the others following him. He had just turned down a hallway searching for Clary when he heard several yowling screams. Immediate concern for Clary flooded him. Her voice sounded harsh and raw. What was Sebastian doing to her? He sped up his pace, running in the direction of the screams.

"Clary?! Clary where are you?!" he called, hoping she would be able to get to him.

"Jace?" he heard Clary call back.

He rounded a corner and ran into something. It was actually a person. A small red headed person who ended up falling from the impact.

"Clary," Jace breathed, relieved. "Are you hurt? Where's Sebastian?"

"I'm fine, Jace. Sebastian was the one screaming, not me," she reassured him.

"What did you do to make him make all those unnatural noises?" Magnus asked.

"I dropped a ferret down his pants," Clary said, calmly.

"You what?" Jace asked, shocked.

"Oh, that poor, poor ferret," Jude lamented at the same time.

"Is Sebastian still where you left him?" Isabelle inquired.

"It sounds like he is," Clary replied.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	15. Chapter 15

Chapter 15:

The group made their way to the room Clary had left Sebastian in. He was still there wrestling with the ferret, which had made its way out of his pants and now seemed very determined to latch onto Sebastian neck.

Magnus snapped his fingers and the ferret disappeared. Sebastian jumped up to face the group. He glared at them angrily.

"What are you doing here?" Sebastian demanded, angrily.

"Apparently, saving you from a ferret," Jace answered, flippantly.

Sebastian snarled and sprang at Jace, knocking him to the floor. The two boys struggled for several minutes, throwing punches and kicks until Sebastian seemed to gain the upper hand. He flung Jace into the wall. Before Sebastian could do anything else, Magnus raised his hand and wiggled his fingers at Sebastian. Sebastian froze, unable to move.

"What did you do to him?" Alec asked.

"I froze him," Magnus explained.

"Couldn't you have done that a few minutes ago?" Jace asked.

"No. You were in the way," Magnus replied.

"What do we do now?" Simon inquired.

"We have to destroy the mango tree and kill Jax," Magnus said.

"Kill Jax?" Clary asked.

"We might not have to kill him. Sebastian's spirit might exit Jax's body just by us destroying the mango tree, but if it doesn't then we'll have to kill him," Magnus said.

"Where's the tree?" Isabelle questioned.

"Probably outside, or in a greenhouse somewhere," Jace said.

The search for the mango tree began. They soon found a small grove of mango trees in the courtyard.

"Which mango tree is it?" Simon wondered aloud.

"It will take way too long to destroy all those trees!" Clary moaned. "I'm guessing it will take more than just chopping down the tree. We need to make sure to get the roots as well," Clary observed.

Magnus snapped his fingers again and the trees disappeared.

"Where did they go?" Simon asked.

"I transported them all to the sun," Magnus responded.

Magnus wavered on his feet.

"Magnus, what's wrong?" Alec asked, concerned.

"I've just used too much magic. I'm beginning to weaken," Magnus told them.

"Will Jax be able to get out of the freezing spell you put on him?" Jace inquired.

Magnus gave a brief nod before slumping to the floor, looking weary.

Jace took off for the room they left Sebastian in, Clary running after him.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	16. Chapter 16

Chapter 16:

They reached the room, only to find it empty. They began searching, and found Sebastian in the kitchen. Blood was seeping through his pants where the ferret had bitten and scratched. Scratches extended up under his ripped shirt. He glanced around, and when he saw them he quickly grabbed a knife from a block on the kitchen counter. Sebastian hurled the knife at Jace. He nearly hit Jace, but at the last second Jace leaped out of the way. Jace pulled out a seraph blade and blocked Sebastian's next blow.

The two men fought back and forth for a few minutes. Sebastian seemed to be tiring; his attacks were fewer and farther between. He didn't seem to have the same amount of energy he had before. Sebastian ended up defending himself more than attacking.

It must be because the tree was gone! Clary realized. It must be making him weaker. Jace must have come to the same realization because he attacked more viciously.

By this time the others had caught up with them. They all watched as Jace drove his seraph blade through Sebastian's chest. Jace yanked his blade out of Sebastian, and Sebastian fell to the ground. Sebastian's glassy eyes stared off into the distance, not really looking at anything.

"What do we do with body?" Alec finally asked.

"As soon as Magnus feels up to it, maybe he could send the body to the same place the mango trees went," Jace said.

"Should we tell the Clave?" Simon inquired.

"We'll have to inform them about Carl," Isabelle answered.

Clary made a portal to the New York Institute. The group went through the portal taking Jax's dead body and Carl along with them. Once at the Institute Jace called the Clave to inform them of what happened. The Clave told him they would send a representative and to detain the warlock.

Jude didn't stick around. Even though he had excepted that Jax wasn't a good person a long time ago, it was still hard for him to see him dead. They had spent ten years of their lives together, after all.

The Clave representative showed up a couple days later.

There was a knock on the Institute door. Clary opened it to find Robert Lightwood standing on the steps to the Institute.

"The Clave sent me for the warlock," Robert said as way of greeting.

"Alright. Come in," Clary invited.

Robert followed Clary through the halls of the Institute until they came to the room Carl was being held in.

Isabelle exited the room, holding a tray just as Clary and Robert arrived at the door.

"What were you doing in there?" Clary asked.

"I was bringing our prisoner some food," Isabelle replied, holding up the tray as proof.

"We're supposed to keep Carl in our custody, not torture him," Jace said, coming up behind Clary.

Isabelle and Jace both greeted Robert.

"Are you going to stay long?" Jace inquired.

"No, I have to head back to Idris today. I only came for the warlock," Robert replied.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	17. Chapter 17

Chapter 17:

It was a few days later that Clary started to notice something was off with her child. Her normally sweet young Stephen who loved to train with weapons and draw was now acting more aggressive. He would get angry and throw fits about the smallest of things.

It wasn't only Stephen that seemed to be different, Liz was also acting strange. Liz was usually a fashion savvy girl who also loved comics and training. Now she was moody and easily angered. It was like the two children were infected with something that made them act differently. They acted like Sebastian, Clary realized.

#

It was strange. Stephen didn't know why he felt so angry all the time. It wasn't even like this happened gradually. He suddenly just felt so pissed off at everything. Nothing was right anymore and didn't know how to fix it. He didn't even know what he needed to fix.

Liz had said she was feeling the same way. She was the only person he didn't find himself angry at. She was his best friend. They had been friends for as long as he could remember, and since he was so young her could remember lots of his early life.

"What are you doing?" Stephen heard Liz ask when she found him sitting in the library reading a book.

"I'm fighting a hoard of demons," was his witty answer. "What does it look like I'm doing? I'm reading a book." A long with his father's love of weapons and training, Stephen had also inherited the Herondale charm.

Liz rolled her eyes, used to Stephen's sarcastic ways. "I know you're reading. What are you reading and why?"

Stephen looked at the cover of the book. "I'm reading _Sea of Monsters_ the second book in the _Percy Jackson and the Olympians_ __series," he said, holding up the book.

"Have you gotten to the part where Hermes claims to have invented the internet?" Liz's eyes lit up, talking about the Percy Jackson series.

"Does it look like I've gotten that far in the book?" Stephen held up the book, showing he was only a few pages in. "Why do you always have to spoil the story?" he snapped, feeling a sudden surge of anger.

"Woah! What happened to your eyes? They turned black for a second," Liz exclaimed.

"What do you mean?" Stephen asked.

"I mean they went from their usual green to a pitch black color. Even blacker than mom's eyes," Liz explained. "It was like when Luke's eyes turned from blue to gold when he turned into Kronos in the Percy Jackson books, except yours turned from green to black."

"I have no idea what you're talking about," Stephen said.

"Your eyes changed color," Liz repeated.

"Stephen?! Liz?! Where are you two?" the two children heard Clary call.

"We're in the library, Aunt Clary!" Liz shouted. "Should we tell her that your eyes changed color?"

"No. You were probably just imagining things," Stephen said.

"I was not imagining it," Liz protested.

"Imagining what?" Clary inquired, coming into the library.

"Nothing," Stephen said at the same time Liz spoke.

"His eyes changed color," Liz said, ignoring Stephen's glare.

"What color did they change to?" Clary asked.

"Black," Liz replied.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	18. Chapter 18

Chapter 18:

Black? Clary thought. Stephen's eyes had changed to black? What did that mean? Did that mean her son was going to become like Sebastian? No, he couldn't! Not Stephen! Not her son! She wouldn't let that happen, no matter what! She would get to the bottom of what was happening.

"Stephen," she said, slowly, "I need you to tell me everything that's been going on lately. I need you to tell me if you have been experiencing any strange feelings or physical changes."

"Nothing's happening to me. I'm fine," Stephen insisted. "Liz was just imagining things."

Stephen got up and left the library.

"Liz, have you noticed anything strange going on with Stephen lately?" Clary inquired.

Liz didn't want to betray Stephen's trust. He had asked her not to say anything. But he had changed and she didn't know what to do. She should tell Aunt Clary. Aunt Clary was Aunt Clary. She would know what to do. She always did. "Yeah, he's been angry lately. And just now his eyes changed."

"Thank you, Liz. I came in here to tell you and Stephen lunch was ready. Can you tell Stephen?"

"Yeah."

Clary got up from where she had sat down on the couch and went to find Jace. She needed to tell him what was going on.

She found Jace in the training room, sparing with Isabelle.

"Liz said she saw Stephen's eyes change color from green to black," Clary told both Jace and Isabelle.

Jace dropped his weapon. "What?"

"She said he's been acting angry lately, and that just now when they were in the library his eyes changed from green to black," Clary repeated.

"Is this some kind of side effect from the mangoes Sebastian was sending us?" Isabelle asked, worriedly. "Is the same thing going to happen to Liz?"

"I don't know. We should call Magnus," Jace suggested.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	19. Chapter 19

Chapter 19:

"They're going to try to take you to Magnus. You can't let them," a voice spoke inside Stephen's head.

"What? Who's there?" Stephen looked around, looking for the source of the mysterious voice.

Stephen was currently in his room. He couldn't believe Liz had gone and told his mom that his eyes changed color after he had told her not too. Liz was always doing stuff like that. It was like she couldn't keep a secret.

Stephen sighed. Even if Liz couldn't keep a secret, he couldn't stay mad at her long. He heard a knock on his door.

"Stephen, lunch is ready!" Liz said, opening the door.

"You should quit being friends with her. Her big mouth will only become a nuisance," the voice spoke again.

"Who are you? Why can I hear you in my head? Are you a silent brother?" Stephen thought at the voice.

Stephen had learned about the silent brothers recently. He had learned that they could speak in your mind.

"I'm not a silent brother, Stephen. Right now it's not important who I am. Right now I have chosen you to be my new body," the voice said.

"New body? Are you going to try to take my body from me? How would you do that? Are you a demon?" Stephen asked the voice inside his head.

The voice chuckled. "Some might say I'm a demon. That's why you must not tell them who I am."

"Who are you?" Stephen repeated the question inside his head.

"I'm your Uncle Sebastian," the voice answered.

Before Stephen could ask the voice who claimed to be his uncle any more questions, Stephen was interrupted by Liz. "Are you paying attention? Did you hear what I said?"

"I'm heard you. You said lunch was ready," Stephen reminded her.

"Right. Aunt Clary said lunch was ready," Liz said.

"We should go eat," Stephen urged.

"Remember. Don't let them take you to Magnus," the voice inside his head reminded him.

"What happens if I do let them take me to see Uncle Magnus?" Stephen asked.

"I will make you hurt Elizabeth," Sebastian threatened.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	20. Chapter 20

Chapter 20:

Stephen was in the kitchen of the Institute sitting beside Liz, eating lunch. He heard people enter the kitchen and looked over to see his mom, dad, and Aunt Izzy.

"Hey, Bud, how would you like to go see Uncle Magnus and Uncle Alec today?" Jace asked him.

Stephen was about to answer that he would really like to go see them when he remembered what the Sebastian guy had said. He didn't want Liz to get hurt. Much less be the one to hurt her. The voice couldn't belong to anybody related to him. Nobody he was related to could ever be so mean, could they?

"No," Stephen said, firmly.

"Come on, you love to visit Uncle Magnus and Uncle Alec," Jace cajoled.

It was true he did love to visit his uncles. He loved the way the blue sparks danced around Uncle Magnus's fingers when he did magic. And Uncle Alec was helping him learn archery. But no, he couldn't hurt Liz.

"No! I don't want to go!" Stephen shouted and stomped out of the kitchen.

#

Jace and Clary watched as their son stormed off.

"Let's have Magnus come here, since Stephen doesn't want to go to him," Clary proposed.

They called Magnus to request his assistance.

"What can I help you with this fine day?" Magnus inquired when he arrived at the Institute.

"Where is Alec?" Jace asked, not seeing him with Magnus.

"Alec is at our apartment with a severe case of the sniffles," Magnus answered. "Now would you kindly tell me what seems to be the problem?"

"Something is terribly wrong with Stephen," Clary said.

"Really? What's wrong with him? Has he suddenly become hideously deformed? If that's the case, there is only so much I can do," Magnus said, facetiously.

"Magnus this is serious," Clary admonished. "Something is wrong with our son. He's been acting different, and earlier Liz said she saw his eyes change from green to black."

"People's personalities change. And as for his eyes, sometimes young peoples' eyes change color," Magnus said.

"Babies eyes will sometimes change color. Not six year olds. By the time a child is six you can be sure of their eye color," Clary corrected.

"Could this have anything to do with the mangoes Sebastian was sending us for all those years?" Jace questioned.

"Perhaps I should examine Stephen," Magnus answered.

"That may be a bit difficult," Clary confessed. "He was adamant about not seeing you."

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	21. Chapter 21

Chapter 21:

"What kind of side effects could the mangoes have on Stephen?" Jace asked.

"The mangoes were infused with Sebastian ghosty bits… Stephen ingested them," Magnus was thinking aloud.

"But so did the rest of us," Jace interrupted. "It's not affecting Clary or me that way. Liz isn't effected to that extent."

"Like I was saying... Stephen started ingesting the tainted mangoes at the age of three. He wasn't infected with demon blood before he was born, as Sebastian was. It is possible the effects of Sebastian's ghosty bits will wear off," Magnus explained.

"When Jax ate the mango Sebastian had been tied to, he became possessed by Sebastian. Stephen isn't going to be possessed is he?" Clary asked.

Magnus thought about it for a minute. "It's possible. Sebastian was split between the tree and Jax before. Now he can concentrate himself all on Stephen. Or Liz. Although, from what you've told me he seems more focused on Stephen."

"My poor baby!" Clary wailed. "What are we going to do? If we don't get Sebastian out of Stephen soon, he will possess my son!"

"Shh, shh," Jace comforted. "We're 'Sebastian Slayers' remember. We'll defeat Sebastian and save our son."

"Sebastian might not be able to possess Stephen as easily as he did Jax. Jax let Sebastian possess him. If Stephen fights Sebastian, it will make it more difficult for him," Magnus stated.

"Stephen is a Herondale. He won't succumb to a weasel like Sebastian," Jace said.

Clary hoped desperately that he was right.

#

Stephen listened in on the conversation his parents were having with Magnus. If he was strong enough, he could fight Sebastian and keep him from possessing him. That's what he would have to do. He didn't want to hurt anybody. He wanted to grow up to become the best shadowhunter of his generation, just like his father.

"You cannot fight me," Sebastian's voice rang out inside Stephen's head.

"Wanna bet," Stephen challenged.

"I will make you regret trying to fight back," Sebastian promised.

"I'll make you regret trying to take me over," Stephen countered.

"You definitely have your mother's fire," there was a hint of excitement and fondness in Sebastian's voice.

"I also have my father's strength," Stephen boasted.

"Your father is weak," Sebastian sneered.

"No, he's not. He defeated you before, didn't he?" Stephen said.

Sebastian didn't answer.

"If my father is weak then you are weaker," Stephen insisted.

Stephen suddenly doubled over in pain, crying out. A sharp pain was shooting through his head. It felt like something was trying to take over. He could feel cold fingers grasping at his soul, trying to get in.

Stephen heard distantly the sound of his parents' voices as the rushed to him after hearing his cry of pain. Stephen slowly succumbed to the darkness that was trying to possess him. The last thing he heard before he blacked out was the sound of his mother's voice desperately calling to him to fight.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	22. Chapter 22

Chapter 22:

Clary looked on in horror as her son writhed on the ground in agony. All of a sudden he stopped, becoming extremely still. When Stephen raised his head and opened his eyes, Clary found herself looking at the pitch black eyes of Sebastian.

"Hello, Little Sister," possessed Stephen greeted. "What do you think of my new body?" he grinned, nastily.

"Get out of my son's body!" Clary screamed. "Leave Stephen out of this. It has nothing to do with him. If you must continue to torture me, do it some other way," she pleaded.

"How sweet. You actually care about your child," Sebastian observed. "How unlike your mother. No. I don't think I'll be vacating this body. I like it… For the most part. It is kind of annoying being child sized. Again."

#

Jonathan Morgenstern watched as Clary and Jace pleaded with Sebastian to leave their son's body. Jonathan hated Sebastian with a passion. Sebastian had been the most evil part of himself, since he had been infused with demon blood while still in his mother's womb. They had been one, and he hadn't known what it was like to be free of the demon until heavenly fire had purged the demon blood from him at his death. Once cleansed, Jonathan could see that the demon blood had ruined his life, making his mother and sister hate him. He was still puzzled about how the demon had become a separate ghost, since demons were supposed to return to their own dimension when they were killed; he supposed perhaps the demon had never been a real demon, but rather a part of himself, made evil by the demon's blood. He was glad to be rid of that part, but also still felt tied by responsibility to try to stop Sebastian from continuing to harm his family.

After Clary had set him free, Jonathan had wished desperately for a way to repay the debt he owed her. The debt he owed because of Sebastian. His wish had been granted by some power higher up, and now he guarded the New York Institute and its inhabitants.

He needed to protect them now. Sebastian was harassing them, and he needed to protect them. He needed to somehow evict Sebastian from Stephen's body and banish him from this world forever. Getting Sebastian out of Stephen's body would be easier than banishing him from the world. All he would have to do was wait until Stephen's body went to sleep. Sebastian wouldn't continue to reside in the body after it went to sleep. Sebastian was a ghost and ghosts didn't need to sleep. They didn't need to eat or go to the bathroom either. It meant they had oodles of free time. Even though ghosts didn't need to sleep, Stephen's body was still living, meaning it still needed restful sleep. Jonathan guessed that Sebastian's plan was to move between Stephen and Liz, so he wouldn't have to waste time while his physical body was sleeping. Jonathan's plan was to intercept Sebastian as he moved; he just hoped nothing too bad would happen while Sebastian was still in Stephen's body. If it did, Jonathan didn't know what he would do. There really wasn't much he could do without harming Stephen as well.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	23. Chapter 23

Chapter 23:

Clary glared at Sebastian. He was refusing to exit her son's body. Suddenly, Sebastian looked to the side. He was staring at something. Clary looked to where Sebastian's gaze was fixed. She didn't see anything.

Sebastian's grinned, "It looks like we have an unexpected guest. If it isn't my old pal and pain in the conscience. How are you doing Jonathan now that we're separated?"

Jonathan? Clary momentarily flicked her gaze to Jace. Sebastian wasn't looking at him. If Sebastian wasn't talking to Jace, who was the Jonathan he talking to? Also why was he calling him a pain in his conscience? Had this other Jonathan been friends with Sebastian? Had this Jonathan tried to steer Sebastian away from his evil tendencies? Where was this Jonathan? Was there a super powerful glamor on him that she couldn't see through no matter how hard she tried, or had Sebastian simply gone cuckoo and started seeing things? There were so many questions running through Clary's head.

"Do you see anybody?" Clary quietly whispered to Jace and Magnus.

They moved off to the side where they could converse quietly and hopefully without Sebastian hearing them.

"No, I think he's finally lost it," Jace answered.

"You didn't think he was crazy before?" Magnus asked.

Jace thought about it. "No," he answered. "He was an evil mastermind, but he wasn't crazy. He was a sociopath."

"You're right," Magnus sighed. "He's never been crazy. I suppose he could be talking to another ghost," Magnus speculated.

Clary's brow furrowed as, in her head, she replayed what Sebastian had said upon seeing Jonathan, "Did he say, 'now that we're separated'?"

"Yes," Jace said, turning to look at her. "Wait, you don't think… He couldn't be… How would that even be possible?"

"Could the heavenly fire have separated the part that was tainted by demon blood from Jonathan?" Clary asked.

"Maybe," Magnus murmured. "The heavenly fire was supposed to burn away all that was evil."

"But wouldn't that have completely destroyed the Sebastian part since he was pretty much created by the demon blood?" Jace inquired.

"I honestly don't know," Magnus replied.

Clary looked back at where her possessed son seemed to still be talking to Jonathan. Could it be the ghost of her brother? The one she was supposed to have. The green eyed white haired boy who would have been there to protect her. How would that even be possible? It completely boggled her mind.

If Jonathan was no longer part of Sebastian, why hadn't he moved on to the next world or done whatever it was people did when they died? Why was he still here? Had the heavenly fire really separated Jonathan from Sebastian? Was Jonathan's ghost going to be the Jonathan Clary had always imagined and wished for, or would he be consumed by Sebastian's power as he was before?

"If I can put a freezing spell on Stephen, Sebastian will most likely leave his body. After all, he has no use for a body he can't move," Magnus' reasoning tone interrupted Clary's thoughts.

"Wouldn't he just move to Liz?" Jace asked. "She ate the mangoes too. There's nothing stopping him."

"We'll have to hurry and hope we can reach her before Sebastian does. If Jonathan is here, and all the evil was burned out of him by the heavenly fire, he might help us as well," Magnus said.

"What good does that do us? Even if we get to Liz before Sebastian, we can't exactly stop him from possessing her. We can't see him or fight him when he's a ghost," Clary pointed out.

"I'll put a freezing spell on her as well. Without a body Sebastian can use, he will have nowhere to go," Magnus told them.

"What's to keep him from hanging around until we unfreeze Stephen and Liz?" Jace questioned. "Then he will just possess one of them as soon as they are unfrozen. I'm thinking your plan has some major problems."

Magnus sighed. He wasn't explaining his plan well at all. "We need to trap Sebastian outside of a body. Once Stephen is frozen, Sebastian's going to leave Stephen's body and try to rush to Liz's. We need to make sure we get to Liz first and freeze her as well. I would put up an energy barrier, but Sebastian would just be able to draw the energy into himself and use it against us. We'll just have to rush really fast. When both Stephen and Liz are frozen, Sebastian will have nowhere to go, and we can get rid of him."

"You could have just told us that from the beginning," Jace grumbled.

"It's not my fault you're so slow," Magnus huffed.

"Just help us, please, Magnus," Clary implored.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	24. Chapter 24

Chapter 24:

"Of course," said Magnus.

He lifted his hand and made an elaborate gesture in the direction of Stephen. Stephen froze. A black mist seeped out of Stephen's mouth and dissipated into the air. As quick as they could they dashed for Liz's room.

When they got to Liz's room, they found it empty.

"I think we should probably have figured out where Liz was before we enacted the first part of our plan," Clary observed. "Sebastian could be taking over her body right this instant."

Fortunately for Clary, Jace, and Magnus, Liz chose right then to return to her room.

"What are you guys doing in my room?" Liz inquired.

"I'm sorry, Sweetheart, but I have to do this," Magnus apologized. He snapped his fingers and Liz froze, a look of confusion on her pretty young face.

"How come you made an elaborate gesture when you froze Stephen, but you only snapped your fingers when you froze Liz?" Jace questioned.

"Does it really matter what gestures I make when I'm casting a spell?" Magnus countered.

"Not really," Jace conceded.

"Now is not the time to wonder over what gesture Magnus makes. We need to go get rid of Sebastian before he realizes we've frozen Liz as well and decides to just sit around in either Stephen or Liz's bodies until we unfreeze one," Clary urged.

#

Sebastian growled in frustration as he blocked yet another attack by Jonathan. Jonathan was supposed to be dead. He was supposed to be in heaven or wherever it was he was supposed to go, not here. Another blast of energy hit Sebastian and the lights in the room flickered.

Jonathan was pulling energy from any place he could. The lights, kitchen appliances, personal technological conveniences, and pretty much any other place he could get energy from. Sebastian was strong and took all of Jonathan's strength to fight him.

Sebastian began pulling in as much energy as he could. If he was going to defeat Jonathan, he would need to disable him as swiftly as possible. Then he could destroy him, sending him back to the land of the dead. Sebastian grinned as he felt the energy building.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	25. Chapter 25

Chapter 25:

Jonathan felt Sebastian stockpiling energy. He needed to counteract it, or he would be destroyed and the world would become Sebastian's playground. Worse, his own nephew would be Sebastian's tool. Jonathan tried to intercept the energy flowing to Sebastian, but he was too strong.

"You might as well give up now," taunted Sebastian. "There's no way you can win." His grin was feral as he looked at Jonathan, and his eyes were wild and sparked with a malicious gleam.

"No," Jonathan grunted, redoubling his efforts to stop the build-up of Sebastian's energy.

Jonathan was distracted by a small burst of energy flying at him.

"See, you're already losing. If you give up now, I'll let you continue on as ghost on this earth," Sebastian promised.

"Your promises mean nothing. I won't let you hurt Clary and her friends and family or anybody else. Ever. Again!" Jonathan shouted the last part.

He was finally able to block some of the energy going to Sebastian and redirect it. Jonathan began to build-up his own stockpile of energy, using the energy siphoned from Sebastian.

"Wrong choice, Jonathan," Sebastian sneered. He took in a sudden burst of energy and flung it at Jonathan.

#

Sebastian watched as the energy sailed through the air and hit Jonathan square in the chest. It sent him flying backwards. As soon as Sebastian saw he hit his target he took off for where he knew Liz was. He was able to feel her location through the connection created by the mangoes. If he was able to enter her body, he would be safe from any more attacks by Jonathan. Assuming Jonathan survived the blast of energy that just struck him. Besides, once in Elizabeth's body, he could convince his sister to have the warlock remove the freezing spell from Stephen's body. Sebastian would prefer to not spend his life in the body of a girl. He was a boy and liked it that way.

Sebastian arrived in Liz's room to find Clarissa, Jace, and Magnus already there. Elizabeth wasn't there though. Where was she? It didn't look like Clarissa and her friends were in a hurry to find Liz. They must have already frozen her and hid her. That's why he couldn't locate her anymore. Great! Just Great! The only other person he could possess was frozen as well. If he couldn't possess one of the children, he couldn't be with his sister. What was he supposed to do now? They couldn't keep the children frozen forever, he thought. If they did, they may as well just kill them. He would have to wait them out, Sebastian decided.

"I'm afraid waiting them out won't be possible. I'm not gone, so I'm going to get rid of you once and for all!" Jonathan said from behind Sebastian.

Sebastian whirled around to face Jonathan. He looked different somehow. Stronger maybe? How could that be possible? He should be extremely weak, trying to recover, assuming that he would have survived at all. But no, he was here now, looking stronger than ever.

No matter. He would destroy him, and make sure he did the job right this time.

"I see you survived," Sebastian observed. "No matter, I'll make sure you're gone for good this time." He smirked and shot an energy ball at Jonathan.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	26. Chapter 26

Chapter 26:

After Sebastian's first blast, Jonathan laid on the ground, stunned. He was weak and could barely move. He needed to get up and stop Sebastian. He couldn't though, he was stuck to the ground as if a heavy weight had been set on his chest. His limbs felt like somebody had tied them to the ground, and his head pounded. He was dead and could still get hurt, he thought, sourly.

" _Help."_ He thought. " _If there is anybody up there with the slightest bit of mercy, please help me stop Sebastian from hurting anybody else."_

A bright light ball began to glow over his chest. It shown brighter and brighter. Jonathan thought he would go blind from the brightness. The ball of light descended into his chest. Jonathan suddenly felt lighter, stronger, faster, more energized than before. He felt as if he could take on a hundred of the strongest demons and win. He grinned. He was ready to destroy Sebastian.

Jonathan found Sebastian in Liz's room, waiting for Magnus to unfreeze her. Jonathan glared at Sebastian's back and challenged him. Sebastian turned and hurled a ball of energy at him. Instead of trying to dodge the blow, Jonathan held out his hand and caught the ball of energy. He absorbed it into him, using its power to further strengthen him.

"What…? How did you do that?" Sebastian asked, bewildered and shocked. It was rare that anything shocked Sebastian. Or if he was surprised, he didn't usually show it.

Jonathan grinned. "I'm able to do this because I have heaven backing me."

Sebastian's eyes flashed with fear and anger. Jonathan felt him pulling the energy towards him. He blocked it and smirked at Sebastian.

Jonathan amassed a large amount of energy, taking energy from both Sebastian and the surrounding energy sources. Sebastian realized the strength of Jonathan's ball of energy and moved behind Clary, Jace, and Magnus.

Jonathan and Sebastian may have been ghosts, and were unable to touch physical objects, but that didn't mean a giant ball of energy wouldn't harm a living being. It would harm a living person just as much as it would a ghost.

Jonathan growled in frustration. As long as Sebastian was around Clary and the others, he could not launch his attack. He needed them to move. He hoped they saw the energy and moved. It was a giant ball of energy after all. You would have to be blind not to see something like that. It wasn't like the energy was confined to the dead.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	27. Chapter 27

Chapter 27:

Clary, Jace, and Magnus were standing there talking. They didn't know where Sebastian was. They knew he would eventually come for Liz if wasn't there already. They had hidden Liz, hoping it was before Sebastian had arrived in the room.

The lights began flickering before going out completely. The room got suddenly cold as if all the life had been sucked out of it. Although since she was still alive, Clary assumed all the life had not in fact been sucked out of the room. Unless she was actually dead. But anyway, she was getting distracted from the matter at hand.

"What's going on?" Jace asked.

"I think Sebastian and Jonathan are battling it out in this room," Clary answered.

"If we stay here, we'll only end up getting hurt or being in Jonathan's way." Magnus spoke.

Clary glanced towards the door and her eyes widened. A giant ball of what looked like lightning was forming in front of the door.

"Uhh… Magnus? We might have a slight problem," Jace commented.

Magnus glanced to where both Clary and Jace were looking.

"We'll have to go out another way," Magnus decided.

"How else are we supposed to get out? I could just jump out the window, but you guys would be killed," Jace pointed out.

"I can create a portal. You and Clary get Liz from where we hid her and go through," Magnus suggested. "I'll meet you on the other side."

"Sounds like as good a plan as any," Clary agreed.

Magnus walked over to the wall and began to make a portal. All of a sudden the hair box on Liz's dresser shot off the dresser and slammed into Magnus's hand. Magnus cried out in pain, cradling his injured hand.

"Magnus, are you all right?" Clary cried, rushing over to him.

Jace had picked up a frozen Liz and was unable to rush quite as quickly to Magnus.

"I think my hand is broken," Magnus replied. "I won't be able to concentrate on making a portal with the pain in my hand."

"Clary, do you have your stele?" Jace asked.

Clary quickly searched her pockets, finding them empty.

"No, I left it on the kitchen counter," she suddenly remembered.

"I have mine in my left front pocket," Jace turned to give Clary access to his left front pocket. "You can borrow it and make a portal."

Clary snatched the stele from Jace's pocket and began drawing a portal rune. The portal opened and they stepped through just as another unidentified flying object was hurled at them.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	28. Chapter 28

Chapter 28:

Jonathan saw his sister along with Magnus and Jace, carrying Liz, exit the room through a portal. Now he could concentrate on destroying Sebastian once and for all.

Jonathan turned all his attention on Sebastian. He drew in a large burst of energy. Jonathan threw the ball of energy at Sebastian as hard and fast as he could. Jonathan saw Sebastian's eyes widen with shock and horror as the ball of energy sailed through the air and hit him smack dab in the chest. Sebastian didn't have time to react before the energy disrupted his ghostly spirit and caused him to leave the world of the living.

It was over. The fight with Sebastian was over. He had won! For the first time in his life – or more like death – Jonathan had defeated Sebastian. "Thank you," he whispered.

Jonathan felt a great weight lifted from his shoulders. A bright white light with green around the edges began to shine above him. Jonathan looked up.

"Come, you have fulfilled your debt. It is time for you to move on," a voice said.

Jonathan moved towards the light, happily. He had paid his debt to Clary and the others. He felt light and free. He felt ready to move on from this world. Jonathan was engulfed in the light and lifted away.

#

Clary and the others landed next to Stephen. Clary knelt down on the ground and began drawing another portal to take them outside the Institute. Being inside probably wasn't the safest place to be when two ghosts were fighting. One armed Jace grabbed Stephen and went through the portal after Mangus. Clary followed.

They landed on the grass outside the Institute and turned around just in time to see a bright burst of light. The Institute seemed to fall completely silent for a few moments then another light appeared. This light wasn't like the glow the ball of energy had emitted. This light had something heavenly about it, like the heavenly fire, only slightly different. Something good. The light suddenly intensified before vanishing completely.

"Does that mean the fight is over?" Clary asked.

"Perhaps," Jace responded. "I'll go in and check."

Clary dashed after him as Jace headed into the Institute. Before she could enter, Magnus stopped her.

"Don't go. If it's not actually safe, there are still people who need you," Magnus said.

"And there aren't people who need Jace?" Clary countered, slightly offended on Jace's behalf.

"Of course there are people who need Jace. There are also people who need you, like Stephen. He shouldn't lose both his parents at once. If Jace gets hurt, he will need you more than ever," Magnus said.

Clary sighed. Magnus was right, but still… It didn't feel right to just let Jace walk into a potentially dangerous situation without her. A few minutes later Jace came back perfectly okay.

"It all looks clear," Jace reported.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	29. Chapter 29

Chapter 29:

They entered the Institute, still careful of any traps that Jace may not have noticed.

"Can we unfreeze the children now?" Clary asked.

"Let's check out the Institute a little more thoroughly first," Magnus suggested.

Jace handed Stephen to Clary, and continued to carry Liz. "It would probably be best not to leave the children alone while we check out the Institute."

They searched the Institute completely. From top to bottom and vice versa. They didn't find anything. Not even Isabelle and Simon.

"Where is everybody?" Clary questioned.

"Yeah, come to think of it, it is a little bit strange that nobody was here to help us," Jace agreed.

"The location of Isabelle and the daylighter are a mystery. You would think they would want to be around for something like what just happened," Magnus remarked.

"We'll have to ask them when they return from where ever they went," Clary said.

"I believe it's safe to unfreeze the children now," Magnus said, once they had finished searching the Institute.

"Good. The sooner they are unfrozen the better I'll feel," Clary sighed.

Magnus snapped the fingers on his unbroken hand. The children stayed frozen.

"Magnus?" Jace asked.

"Sorry, I'm having trouble concentrating with my broken hand," Magnus winced.

Magnus snapped his fingers again and the children unfroze.

"Woah, what happened?" Stephen inquired.

"Stephen, my baby!" Clary cried, rushing forward to hug him.

"I'm not a baby!" Stephen protested.

Clary didn't comment just held on tighter to her son.

Stephen began to try to wiggle out of Clary's grasp. "Stop hugging me so tight. What happened? Last I remember I was outside the library."

"You don't remember?" Jace asked.

"If I remembered, I wouldn't be asking what happened," Stephen pointed out, dryly.

Clary snorted in amusement at Jace's sour expression.

"I'm being sassed by my own offspring," Jace complained, quietly enough that Stephen wouldn't hear.

"You taught him well, Jace," Clary smiled, patting Jace on the cheek.

"So? What happened?" Stephen asked, insistently.

"Do you remember anybody who may have called himself Sebastian?" Clary asked.

"Yeah, why? Did he do something?" Stephen inquired.

"Honey, he possessed you," Clary said, gently, crouching down to his eye level.

"You mean like a demon?" Stephen asked, trying to process the information.

"Yes," Clary smiled and put her arm around Stephen.

"But everything's good now right? You stopped him and saved me?" Stephen queried in a small voice. "And Liz," he added, seeming to remember something.

"Yup," Jace said.

"Does this mean me and Liz can have ice cream?" Stephen prodded.

Clary smiled and heard Liz yell 'yeah' eagerly.

"Yes, you and Liz may have some ice cream," Clary agreed.

"Hey, save some for me!" Magnus yelled after them as they ran for the kitchen.

Magnus winced again at the pain in his hand.

"We should treat your hand," Clary said.

#

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


	30. Chapter 30

Chapter 30:

It was a few hours later that Simon and Isabelle got back to the Institute. By this time Clary and Jace had treated Magnus's hand and he had headed home. But not before having some ice cream.

"Where have you two been?" Jace asked, raising his eyebrow.

"Simon and I went out on a spontaneous date," Isabelle replied. "Is that a problem?"

"Only if you call Stephen being possessed by Sebastian, Liz nearly being possessed by Sebastian, and Jonathan fighting Sebastian and destroying him a problem," Jace replied.

"What happened?!" Simon's eyes nearly bugged out upon hearing the news.

"Stephen was posses..." Jace started again.

"We heard you the first time," Isabelle interrupted. "Why didn't you call us?"

"We didn't exactly have time too," Jace said, dryly. "It's not like we could hold up our hand and ask if we could wait for you two to get back before things went further."

"So Stephen is possessed by Sebastian?" Simon asked.

"No. Didn't you hear what I said after that? Jonathan destroyed Sebastian," Jace repeated.

"Who's Jonathan?" Isabelle inquired?

"My brother," Clary replied.

"Then who's Sebastian?" Isabelle inquired.

"We don't really know how, but Jonathan and Sebastian were separated. The closest we could guess is that the heavenly fire somehow separated them," Clary explained.

"So now we have Jonathan as a ghost roaming the halls of the Institute?" Simon queried.

"Maybe. We haven't heard anything from him since he fought Sebastian," Jace said.

"The children are all right, right?" Isabelle questioned. "Liz isn't hurt, is she?"

"The children are fine. Last I checked they were both in the library, playing hide and seek," Clary assured them.

"I'm glad everyone's safe," Isabelle said, relieved.

"Yes, and since there is no sign of Sebastian, I sincerely hope he's gone for good," Clary smiled.

"Mmmhmm," Jace murmured. "We can resign our positions as 'Sebastian Slayers' and go back to being ordinary Shadowhunters."

The others smiled and they all headed for the library to check on the children. After all that had happened, they weren't too keen on leaving the children alone for long periods of time.

#

 **The End**

 **Mango, Mango fruit divine,**

 **Mangoes in this box of mine,**

 **Where did you come from?**

 **Why are you here?**

 **Why do you make me feel so queer?**


End file.
